With its complexity, range of motion and extensive use, a common soft tissue injury is damage to the rotator cuff or rotator cuff tendons. Damage to the rotator cuff is a potentially serious medical condition that may occur during hyperextension, from an acute traumatic tear or from overuse of the joint. The accepted treatment for a full thickness rotator cuff tear includes reattaching the torn tendon to the humeral head using sutures. In treating large or massive full thickness tears, accepted practice also can include the placement of scaffolds and patches over the repaired tendon to mechanically augment the strength of the repaired tendon.
For partial thickness rotator cuff tears, and for full thickness tears that do not require mechanical augmentation, a bioinductive implant has been used to induce new tendinous tissue, which biologically augments the tendon and enables healing of partial thickness defects, as well as improved reattachment of full thickness repairs to the humeral head. The healing response associated the bioinductive implant results in integration of the newly induced tissue with the native tissues, which provides a biological connection for load sharing that is not dependent on sutures or some other mechanical anchor or connector. This biological connection is a critically important aspect of biological augmentation because long-term load sharing is not dependent on sutures, which may migrate through the tissues, but is ensured by the continuity of the collagen fibers in the induced tissue with native tissues. The bioinductive implant, however, does not provide any immediate mechanical augmentation; rather, the newly induced tissue provides biological augmentation over time.
Current scaffolds or patches used to augment rotator cuff repairs are designed to provide initial mechanical augmentation, i.e., added strength, at the time of surgery. Use of these implants, however, often do not provide any benefit beyond the immediate postoperative period. Thus, there is a need for an implant that not only provides initial mechanical augmentation, but also provides improved healing.